I have a hibiscus tree that I bought last year. I brought it in for the winter and took it back outside for the summer.
I did buy a hardy hibiscus last year and planted it outside. It has come up again this year.
Most like you have a houseplant hibiscus. You can take it outside for the summer, but bring it inside in the fall.

Scarborough,Ont. Zone 6A LorraineSuburbia is where the developer bulldozes out the trees, then names the streets after them. ~Bill Vaughn

I think all of the tree's are going to be Tropicals, as the Hardy Hibiscus dies back in the fall, in the spring I cut it to the ground, and it starts up again, so this wouldn't work with the tree shape.

Thank you for the pictures. I do have the tropical plant and wish it looked like yours. I had a bad case of spider mites that took all the leaves. now the plant is healthy again but is still just producing leaves. Maybe soon??

Mine seems to bloom whenever it wants. It was getting leggy last winter so hubby chopped it all back to a stubbin' hehe, it' looked pretty pathetic, it's filled in again nicely now. (that pic was from last year). So the plant is very full, but no blooms, I'll try and up it's fert and see if I can't get a few. It was a pretty prolific bloomer in the past.

You know what, that's interesting because my tropical best friend, Candy Wind Hibiscus, hasn't been blooming much this season either. She normally does all year round. Kind of odd that she wouldn't in summer, but I chalked it to my move in May.
She has also been suffering more than usual on the terrace (even falling over twice in the high winds) so I decided to bring her in for good. Don't tell her, but I think she's getting on in years and needs more pampering.
I usually dose her monthly or bi-weekly, depending on the season, with Schultz's African Violet Plant Food, have been doing so for a couple of years (8-14-9). I like the Epsom Salt idea!
Can't find any photos right now.